Our scheduled FTP backup job started failing one night and has failed ever since. We tried upgrading to the latest version 11.3.13 but it didn't make any difference, only now the email says that all databases were successfully copied. But the detailed log shows they were not successfully copied and say things like "Destination error: An existing connection was forcibly closed by the remote host" and "Destination error: Command REST not allowed by policy (502)"
This all started occurring over a weekend when nobody would have be doing anything. The FTP server logs look okay, it doesn't know that it didn't receive the whole file until sqlbackupandftp deletes the file and tries again - sometimes the retry succeeds but now mostly it doesn't.
Any ideas/things I can try?